Surface grinding device



Oct. 9, 1956 F. w. DlTTO 2,765,597

SURFACE GRINDING DEVICE Filed Jan. 4, 1954 4 Sheets-Sheet 1 ATTORNEY Oct. 9, 1956 F. w. DITTO SURFACE GRINDING DEVICE 4 Sheets-Sheet 2 Filed Jan. 4, 1954 flat/25%, OQMQM A T T O R N EY 06L 1956 F. w. DITTO 2,765,597

SURFACE GRINDING DEVICE Filed Jan. 4, 1954 v 4 sheets-Sheet 5 war ATTORNEY Oct. 9, 1956 Filed Jan. 4, 1954 F. w. DITTO 2,765,597

SURFACE GRINDING DEVICE 4 Sheets-Sheet 4 'lllllll; 2.142211-4252331211113:111:2..222122211..2212" A\ E INVENTOR ATTORNEYI SURFACE GRIN DING DEVICE Fred W. Ditto, Lansing, Mich, assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Application January 4, 1954, Serial No. 401,921 2 Claims. (Cl. 51-241) This invention relates to a device for refacing a flat horizontal surface such as a sow block seat formed with in'the base of a steam drop hammer.

in steam drop hammers such as are used in forming bars, billets or sheet metahmembers the forginghammer is driven against a bar, billet or sheet member disposed over a hammer die. The impact received by the hammer die is-transmitted through a sow block adapted to retain thehammer die in position, and against the hammer base or anvil within which the sow block seat is formed. Repetitious impacts of great magnitude are received by the hammer die and are relayed to the sow block seat causing Wear, developing low spots within the seat and affecting the level position of the hammer die. In the past releveling of the hammer die has necessitated completely tearing down the steam hammer, setting up a portable milling machine and re-maching the entire surface of the hammer base or anvil. Such a procedure requires a great deal of time to set up, is a very slow resurfacing process and wastes numerous machine man hours.

It is now proposed to provide a device for refa-cing a horizontal surface such as a sow block seat which replaces the milling process for cleaning and releveling such a surface. It is proposed to provide a device which may be set up within a steam drop hammer or other machine without necessitating completely tearing down such a machine. The device is easily accommodated within a low Working clearance and is operable withina small amount of free lateral space.

The proposed device includes a pair of guide rails which are adapted to be removably secured to supporting surfaces formed upon a work piece. The guide rails are parallelly arranged on opposite sides of the surface of the work piece which is to be refaced. A carriage member is mounted upon the guide rails and is disposed in spaced relation over the work surface. The carriage is adapted to be moved back and forth upon the rails by a reversible carriage drive means compactly arranged within the guide rails. The carriage includes a surface grinder disposed in grinding engagement over the work surface. Means are provided within the carriage member for moving the grinder lateral-1y across the carriageand for adjusting the grinder relative to .the Work surface. The resurfacing device is readily set up for use ina minimum of time, is relatively simple to operate, and enables rapid releveling of a work surface with a minimum loss of machine man hours.

In the drawings:

Figure 1 is a top view of the proposed sow block seat grinder as adapted for mounting on a steam drop hammer and over a sow block seat.

Figure 2 iso side view of the sow black seat grinder shown in Figure 1 wherein the grinder is shown in resurfacing position.

Figure 3 is an end view of the sow block seat grinder showing the drive motor and the mounting of the carriage runner blocks on the hammer base.

Figure 4 is a side view of one end of the proposed grinding machine showing the chain and sprocket drive. A part of the grinder carriage block is broken awayto more clearly show the roller employed therewith.

Patented Got. .9, 1956 Figure 5 is a side .elevational view .of the grinder mounted on the cross arm of the carriage member as viewed in the plane of line 5-5 of Figure 1 looking in the direction of the arrows thereon.

The resurfacing device shown in the drawings has been adapted for use within a steam drop hammer for refacing the sow block seat formed within the hammer base or anvil. The device includes a pair of parallel guide rails adapted ,to be secured as by screws or other means' 8 to the lands 12 on each side of the sow block seat '14. The guide rails :10 are extended beyond-the extremities of the sow block seat 14 andhave their ends secured together by cross members 16 and 18. The upper face of the guide rails 10 are formed as dove tails 20 f upon which carriage runners 22 and 24 are adaptedto ride. The carriage runner-s 2-2 and 24 include vertically disposed rollers 26 mounted within the cut away ends 28 of each runner and elongated strakes 30 secured, as by bolts '31 extending through the runners, to the PPQSite sides of the bottom of each runner and in sliding engage ment with the guide rail 10 about the dove tailed. portion 20 thereof. A cross arm 32 is secured between the carriage .runners 22 and 24 to form, in combination with the runners, the carriage member 34. The carriage member 34 extends across the sow block seat #14 and in spaced relation thereover. The cross arm 32 is secured by fastening means 34 to each runner 22 and 24 in a mannerto assure transverse alignment with such runners. A nut'runner shaft 36 is also extended between the carriage runners 22 and 2/4 and is received at each end within mounting brackets 38 secured to each runner. A surface grinder 40 is vertically mounted upon the cross arm 32 by means of a support member 42 arranged in sliding engagement with the cross arm. The surface grinder '40 includes a horizontally disposed grinding Wheel '44 in parallel relation over the sow block seat 14 to be refaced.

A drive motor 46 is secured to one of the cross members 16 at one end of the resurfacingydevice by means of brackets 48 secured to the cross, member. Any conventionaldrive motor may be employed, however, in the present instance, an air motor is used. The air motor 46 includes a reverse button 50 for reversing the drive direction of the motor shaft '52. The reverse but-ton 50 is manually operated by movement of a slide bar '54 arranged above the motor 46 and having a reverse cam slide 56 secured thereto and adapted to engage the reverse button. The slide bar '54 also includes a run-stop lever cam slide '58 engaging a-run-stop lever '60 associated with the air motor and adapted to control therunning operation of the air motor 46. The drive shaft 52 of the air motor is supported within bearings 62 and has a'drive sprocket d isecured to its outer end. The driving force is transmitted by a chain drive 66 to a driven sprocket '68 secured to a driven shaft '70 extendingtransversely of the guide rails 22 and 24 at one end 'of the resurfacing device. The shaft is mounted within bearings '72 secured towsupport plates 74. The support plates 74 are secured to thecross member 16 and are extended outwardly therefrom to support the shaft'70 beyond the outer ends of the guide rails 22 -and24. Sprocket wheels 76 are secured to each end of the driven shaft and are adapted toeng-age and drive rolling chains 78. Another driven shaft 8t) is secured to the other end of the resurfacing device and is supported within bearings 82 secured to brackets 84 included upon and extended .beyond the other cross member $18. Sprocket Wheels 86 are similarly arranged at the opposite ends of the shaft 86 for receiving the drive chains 78. The ends ofthe chains 78 are secured to the opposite ends of each-of the carriage runners 22 and.24. The bracket'sB-S- secured to the carriage runners "22 and 24' for receiving the ends of the drive chains 78 are provided with means 90 for taking the slack out of the chains. The drive chains are adapted to run within grooves 92 formed Within the sides of each guide trail 22 and 24 and are thereby compactly arranged and protected from obstruction.

The surface grinder 40 mounted on the cross arm 32, as

thus far described, is adapted to be moved longitudinally across the surface of the sow block seat '14 to be refaced. The drive motor 46 is adapted to rotate the driven shaft 70 causing the chains 78 secured to the carriage runners 22 and 24 to move the carriage 34 back and forth over the sow block seat 14 in a direction dependent upon the rotation of the motor shaft '52 as set by the reverse cam slide '56 and dependent upon whether or not the run-stop lever 60 is arranged to provide for running operation of the drive motor 46.

In order that a dead stall condition of the air motor drive may be prevented at either end of the front to back movement of the surface grinder 40, air pilot or check valves 94 are secured at each end of the resurfacing device to brackets 74 and 84. The pilot valves 94 have actuating members 96 disposed in spaced relation adjacent the drive chains 78 and are adapted to be actuated by dogs 98 secured to one of the chains. The dogs 98 are positioned so as to actuate the pilot valves 94 connected by air line 100 to the motor 46 and shut ofif air to the air motor when the surface grinding carriage 34 is near the end of the guide rails 22 and 24 and the grinding wheel 44 is no longer in engagement with the sow block seat 14. Thus if the operator has not reversed the direction of drive of the air motor 46 before the carriage 34 has reached such position the motor will be automatically placed out of operation.

The surface grinder 40 is secured to a support member 42 which is arranged in sliding engagement with the cross arm 32. The support 42 includes a vertical member 102 through which the nut runner shaft 36 is extended. The vertical member 102 is threaded to receive the shaft 36 and is adapted to be moved along the shaft and between the guide rails 22 and 24 by rotation of the shaft. The cross arm 32 includes a vertical member 104 secured to one of its sides. The vertical member 102 of the support 42 is maintained in a vertical position by bearing against the vertical member 104 of the cross arm 32. Slide blocks 106, 108, and 110 are secured to the vertical member 102 of the grinder support member 42 and are arranged in engagement with the top, bottom, and sides of the cross arm 32. A slide block 112 is also secured to the lower end of the vertical member 102 of the support and is grooved to receive the lower end of the vertical member 104 of the cross arm. Adjustable means are provided Within the slide blocks 108 and 110 to assure proper alignment of the support 42 upon the cross member 32. These means include smaller slide blocks 114 and 116 received Within the larger slide blocks 108 and 110 and urged into engagement with the cross arm 32 by adjustment of set screws 118 and 120 threaded within the slide blocks 108 and 110 and engaging the smaller blocks.

The vertical slide block 102 of the support member 42 is provided with a groove 122 within which is mounted a vertical feed screw 124. The surface grinder 40 has a plate 126 secured to its side and adapted to bear against the vertical slide block 102 of the support member. Vertical drive block 128 is secured to the plate 126 and is received within the groove 122 in threaded engagement with the feed screw 124. The block 128 is slidably engaged within the groove 122 and holds the plate 126, and thus the grinder 40, against the support member 42 enabling vertical slide movement of the grinder relative to the support member upon rotation of the feed screw 124. Retainer block 130 is secured to block 102 to hold one end of feed screw 124. A calibrated indicator 132 is secured to the other end of the feed screw 124 to indicate the vertical movement of the grinder 40 and consequently the depth of cut when the grinding wheel 44 is in working engagement with the work surface 14.

In adapting the proposed resurfacing device for use in grinding a horizontal surface the guide rails 22 and 24 are disposed on opposite sides of the surface 14 to be refaced with the carriage member 34 mounted across the rails and over the work surface. The drive motor 46 is adapted to move the carriage 34 back and forth across the work surface 14. Adjustment of the nut runner shaft 36 extending between the carriage runners 22 and 24 is adapted to move the surface grinder 40 laterally across the work surface 14. Adjustment of the vertical feed screw 124 within the grinder support member 42 is adapted to move the surface grinder wheel 44 into the desired engagement with the work surface 14. As the grinder 40 is transversed back and forth along the work surface 14 the operator may manually reverse direction at any time by movement of the slide bar 54 engaging the drive motor reverse button 50. The operator may also stop the movement of the carriage 34 at any time by actuation of the run-stop lever 58. The carriage 34 is adapted to be automatically stopped at either end of the guide rails 22 and 24, unless reversed before reaching such position, by the engagement of the dogs 98 secured to the drive chain 78 with the actuating levers 96 of the pilot valves 94 disposed at the opposite ends of the resurfacing device. The resurfacing device is thus able to reface any portion of the work surface or the entire work surface in a minimum of time with the most simple manual operation required of an operator.

I claim:

1. A sow block seat grinder for use within a steam drop hammer having the drop hammer elevated and the sow block and anvil thereof removed, said sow block seat grinder including a pair of spaced parallel guide rails adapted to be secured to the side walls of said steam drop hammer forming the seat for said sow block. a carriage member mounted upon said guide rails and extended in spaced relation over said sow block seat and beneath said drop hammer, a surface grinder secured to said carriage member and including a grinding wheel disposed in working relation over said sow block seat, reversible carriage drive means secured to said guide rails beyond the limits of said steam drop hammer, and carriage limit stops provided at opposite ends of said guide rails for limiting carriage travel at opposite ends of said rails and beyond the ends of said sow block seat.

2. A resurfacing device including parallel spaced guide rails removably securable to the side walls of a surface to be refinished, a carriage member extended between said guide rails and including guide blocks engaging said guide rails, a lateral and vertical adjustable work tool secured to said carriage member, carriage drive means secured to said guide rails between adjacent ends thereof and beyond said surface to be refinished, said carriage drive means including chain drive means connected to said guide blocks, chain drive return means formed through said guide rails, and means disposed at the ends of said guide rails and operatively connected to said drive means for stopping said drive means upon the completion of work stroke travel by said work tool over said surface being refinished.

References Cited in the file of this patent UNITED STATES PATENTS 

